Pneumatic seat-post for bicycles.



PATENTED DEC. 8, 1903.

E. BROUGHAM. PNEUMATIC SEAT POST FOR BIGYGLES.

APPLIOATIOfi FILED SEPT. 2, 1902.

2 SHEETS-SHEET v1.

N0 MODEL Edwwrdfiwyimd n 98 MO I aw I\ Witnesses Attorneys THENORRISPETERS co. FHOTOLITHQY WASHINGTON, n, c. v

No. 746,279. I PATENTED DEC. 3, 1903..

E. BROUGHAM. PNEUMATIC SEAT POST FOR BIGYGLE81 APPLICATION FILED SEPT.2. 1902.

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, UN T D STATES Patented December 8,

PATENT OFFICE. Y,

.EDWARD BRoUcH M,on BANfDoN, oANADA.

PNEUMA'I 'IC SEAT-POST FOR BICYCLES.

SPECIFICATION formingpart of Letters Patent N 0. 746,279, dated December8, 1903.

Application filed $eptemher 2, 1902. Serial lid-121,765. 7 (No model.)

and useful Improvements in Pneumatic Seat? Posts for Bicycles; and I dohereby declare,

that the following is a full, clear, and exact description of theinvention, such as willenable others skilled in the-art to which it ap-1 pertains to make and use the same.

My invention relates to an improved pneumatic-cushion saddle-postespecially for bicycles, although of course it may find use on otherlike vehicles.

The object of my invention is to improve on the spring saddle-postheretofore in use by providing a device which is both independent of theweight of the user and also which cannot weaken and run down after acertain amount of use, as spring saddle-posts always do. In orderingspringpost applicants must give their approximate Weight-in order that asuitable scale or spring may be supplied; but my pneumatic post hereind'e-;

scribed'will never weaken or run down, and

owing to the fact that it can be filled withany bicycle-pump it can bemade to carry all weights of riders with equal buoyancy and may beadjusted to any degree of resiliency,

tightened up around the seat-post by a clampaccording to the taste ofthe user.

A further object-of my invention is to produce a construction ofseat-post which without the use of complicated rollers is prevented fromturning in its socketin the main post of the frame, while at the sametime itis permitted to slide freely therein by means of a key or pininserted laterally and interlocking the parts together, and thus toenable the saddle-post to be much easier and consequently more cheaplymade.

Another object of my invention is to enable any bicycle having a rigidframe to be converted intoone with a cushion-frame without substantialalteration thereof I accomplish these objects by the combination andconstruction of parts herein shown and described, and which will beparticularly pointed out in the claims. v

In the drawings accompanying this specification, Figure 1 is a sideelevation of a portion of a bicycle-frame provided with my imshown inFig. l.

. thick as its front side 17.

proved saddle-post and comprising the saddle-post itself, the upperportion of the main post of the frame, and the ends of the uppercross-beam and-rear fork. Fig. 2 is a longitudinalcentral section of thesame parts as Fig. 3 is a side elevation of the inner member of thesaddle-post shown to stint in the stationary sleeve, which is shown invertical section. Fig. 4 is a transverse section through the sleeve.Fig. 5 is a side viewot' the wrenchor tool used in setting up thesaddle-post; and Fig. 6 is a side A view of a modified formof'saddle-post, shown partially in central longitudinal section. Figs.7, 8, and 9 are views similar to Figs. 2, 3, and 4, respectively, butshowing a moditied and improved form of seat-post.

The same numerals of reference denote like parts in each of the severalfigures of the drawings.

The nu meral 7 designates the main post of an ordinary bicycle-frame,having at its up-.

shown, issecured atany suitable height, according to the dimension ofthe rider, by

meansof a split clamping-collar ll, which is ing-nnt'12; The seat-postitself consists of two members 13 and 14, each of which is tubular andwhichslide one Within the other and which are separated from each otherat the bottom by a pneumatic cushion15, which resiliently supports themember 13 on the member 1%. The on ter member is, as shown moreparticularly in Fig. 4, bored eccentrically, so that its rear side 16 isabout twice as In practice this seat member 14 will be cut to theordinary external dimensions for a seatpost of the usual patternthat isto say, five and onehalf inches in length and one and five sixteenthsinches in diameter OULSldBr-WhllQ the bore 18 is three-fourths of aninch, leaving one-sixteenth ofan inch for the front andoneeighth of aninch forthe rear wall at 16. The member 14 is, moreover, openat bothends, and its lower endis threadedjnternally, as

shown at 19, and has fitted thereinto a cylin drical plug 20, which hasan external thread adapted to coact with the thread 19 and is ordinarilyabout five-sixteenths of an inch in thickness. This plug 20 is providedwith a central bore 21 of five-sixteenths inch diameter, and at eachside of the bore 21 are drilled two small holes 22. The purpose of theseholes is to enable the nut to be manipulated for screwing up andunscrewing the same, which is done by means of a fork or stapleshapedtool 23, made of an ordinary piece of steel wire bent into U shape andwhich when inserted into the holes 22 enables the plug 20 to be turnedby means of a wrench.

The inner member 13 of the seat-post is made of suitable dimensions toslide easily within the member 14, and the latter is preferably providedat its upper end with a slight chamfer or counter-bore 24 to assist inthe lubrication of the surfaces. This inner member 13 is forged or castwith a solid head 25;

but its lower portion is preferably tubular, having a bore 2b for economizing unnecessary weight and metal. The upper or solid head 25 of themember 13 is shouldered, as shown at 26, so as to provide a stud 27 ofsquared or otherwise irregular section, over which fits the socket-lug28 of the saddle-arm 29, and the upper end of the stud 27 is threaded,as shown at 30, to enable the nut 31 to be screwed thereover, so as toclamp the saddle-arm 29 in position on the stud 27. This construction ispreferably used by me and constitutes a part of my invention, althoughit is not essential to the operation of the pneumatic feature, and I mayconsequently constitute a different form 13 of the member 13, in whichthe saddle-arm 29 is formed integrallyiherewith. Nearthe lower end ofthe member 13 and opposite the recess 26 at the rearsideit is providedwith an axial slot 32,which receives the end of the pin 33, which isshouldered only close to its head, as shown at 34, and screwed intoathreaded socket 35, formed in the rear thickened side of the member 14.The slot 32 is long enough to enable the member 13 to have a certainamount of reciprocation within the socket member 14, and especially tolimit its upward movement and prevent it from coming out. The lower endof the member 13 rests upon a circular metal cap or plate 36, which issecured to the head by a ruhbercapsule 37, having hardened or vulcanizedends 38 and 39. The capsule is adapted to be filled with compressed air,and to this end it has fitted into its lower end a valve'nipple 40,which projects slightly beyond the lower end of the capsule-that is tosay, about five-sixteenths of an inch-so as to extend through theaperture 21 in the plug 20, beingof about the same diameter as thelatter. As shown, this nipple has formed interiorly thereof a valve-seat41, with which coacts a pop-valve 42, having a stem 43, arranged toreciprocate in the valve, and the outer end of the valve may beinteriorly screw-threaded, so as to permit the insertion of any form ofvalve-plug 44. The internal screw-thread of the nipple is of the samesizeas is customary for bicycle-pumps, so that by screwing on the nippleof a bicyclepump the capsule may be pumped full of air, and beingremoved the pumping-nipple may be sealed by the plug 44.

It will be obvious that the above construction provides apneumatic-cushion support for the member 13, which has a resilientreciprocation within the member 14, and the latter may be arranged atany suitable height by the clamping-screw 12. The device is inclosedwithin a small compass, is extremely simple in construction, does notinvolve the use of liquid, and is readily removed and pumped up at anytime and may be adjusted to the weight of any user, and these areadvantages which, so far as I know, are entirely novel in the art.

In Figs. 7, 8, and 9 I have shown a construction which is somewhatsimpler than that shown in the previous figures of the drawings andpreferable also in other respects. The parts are precisely the same inthis modification as in the other figures with the exceptionoftheinnerand outertu bular members, designated in the said modification13 and l4, respecrively, and the interlocking pin, designated 33. Theouter tubular member 14' is in this modification not eccentrically butconcentrically bored and is made an inch or two longer than that shownin Figs. 1, *2, and 3 in order to permit the insertion of a coiledspring 45 between the head of the capsule 37 and the lower end of theinner tubular member 13. This is for the purpose of giving increasedresiliency independent of that imparted by the capsule. The concentricboring of the outer member 14 is rendered possible by the differentconstruction of the interlocking pin 33', which in this case, as shown,extends completely across the outer member and is secured in a threadedsocket 46 in the front wall thereof, while its head is countersunk inthe rear wall, as shown. The inner tubular member 13 has in addition tothe slot 32 another slot 32, parallel thereto, but on the opposite sideof the inner member, and the pin 33 passes through both. This givesincreased resistance to torsion of the saddlepost,besides facilitatingthe construction by avoiding the necessity of boring the outer tubularmember eccentric-ally.

\Vhile I have shown in the accompanying drawings the preferred form ofmy invention, it will be understood that I do not limit myself to theprecise form shown, for many of the details may be changed in form orposition without aifecting the operaliveness or utility of myinvent-ion, and I therefore re- 1. A pneumatic-cushion saddle-post com-'prising an outer tubular member closeda't one end, a post telescopingwithin said outer member, and a cylindrical capsuleinterposed betweenthe inner end of the inner member and said closed end of the outermember, and having a tubular air-valve projecting concentrically througha hole in the latter, whereby a pump. may be externally applied, saidcapsule having a rigid head at its other end and resilient sides.

2. A pneumatic-cushion saddle-post comless diameter than the innerdiameter of said outer member. 4

3. A pneumatic-cushion saddle-post for bicycles, comprising an outermember adapted to be clamped at varying heights in the main post of abicycle-frame, and having a closed lower end with a hole boredconcentrically therethrough, an inner member supporting the saddle atits upper end and telescoping within said outer member, an elongatedcapsule having rigid heads at its ends and expansible sides normally ofless diameter than the interior diameter of the outer member, and atubular air-valve secured in the lower head of said capsule andprojecting through the hole at the lower end of said outer member,whereby an air-pump may be applied to inflate said capsule from theexterior.

4. A pneumatic-cushion saddle-post for bicycles, comprising an outermember adapted to be clamped at varying heights in the main post of abicycle-frame, and having a closed lower end with a hole boredconcentrically therethrough, an inner member supporting the saddle atits upper end and telescoping within said outer member, an elongatedcapsule having rigid heads at itsends and expansible sides normally ofless diameter than the interior diameter of the outer member, a tubularair-valve secured in the lower head of said capsule and projectingthrough the hole at the lower end of said outer member, whereby anair-pump may be applied to infiate said capsule from the exterior, and apin secured in the wall of said outer member projecting radiallyinwardly through a slot in said inner member, whereby rotation of thelatter is prevented.

5. A pneumatic-cushion saddle-post for bicycles and other vehiclescomprising astationary tubular member having a bore from end to endthereof, a cylindrical plug threaded into the lower end of said bore andhaving a central axial bore therethroug h, a resilient capsule adaptedto contain compressed air and resting on said plug, an air-valve communicating with the interior of said capsule and fixed thereto andprojecting through the bore of said plug, an inner member sliding freelywithin said bore and having a limited reciprocation therein, a pinprojecting through the wall of said tubular memberinto a slot formed insaid inner member, whereby to limit the reciprocation of the latter andprevent the same from turning about its axis, and a saddle-arm carriedby the upper end of said inner member.

6. A pneumatic-cushion saddle-post for bicycles, comprisng an outertubular member open at both ends, a concentrically-bored screw-plugfitted into the lower end of said outer member, an inner membertelescoping within said outer member, and an inflatable air vesselinterposedbetween the end of said inner member and said screwplug andhaving a tubular air-valve projecting through the latter.

7. A pneumatic-cushion saddle-post for bicycles, comprising an outertubular member open at both ends, a concentrically-bored A screw-plugfitted into the lower end of said outer member, an inner membertelescoping within said outer member, and an inflatable air vesselinterposed between the end of said inner member'and said screw-plug andhaving a tubular air-valve projecting through the latter, said airvessel having a rigid head 36,

substantially filling the bore of said outer member.

8. A pneumatic-cushion saddle-post for bicycles, comprising an outertubular member open at both ends, a concentrically-bored screw-plugfitted into the lower end of said outer member, an inner membertelescoping within said outer member, an inflatable air vesselinterposed between the end of said inner member and said screw-plug andhaving a tubular air-valve projecting through the latter, said airvessel having a rigid head 36 substantially filling the bore of saidouter member, and a coiled spring interposed between said head 36 andthe end of saidinner member, substantially as described.

In witness whereof I have hereunto set my hand in the presence of twowitnesses.

EDWARD BROUGHAM.

.Witnesses:

S. O. ATKINSON, B. HARTNEY.

IIO

